Automatic crossing gate



sept- 1942- s. MISKELLY 2,295,419

AUTOMATIC CROSSING GATE Filed web 10, 1939 'r Sheets-Sheet 1 Sept. 8, 4s. MISKQELLY 2,295,419

AUTOMATIC CROSSING GATE Filed March 10, 1939 7 Sheets-Sheet 2 |NVE NTORSamqel MLsbellg BY 40 of [11S A'ITORNEY p 1942- s. MISKELLY 2,295,419

AUTOMATIC CROSSING GATE Filed March 10, 1939 7 Sheets-Sheet 3 I iw/////////////////////// 1 /////////////////l/ IIII/lIIIIIIl/IIIIIIII/IlbY/II/II/II/ 5; am I|1u 0 I 22 25 Fig. 4.

To Track INVENTOR Samuel Ma'rkellg.

u). d M

H16 ATTORNEY Sept. 8, 1942. s. MISKELLY AUTOMATIC CROSSING GATE FiledMarch 10, 1939 filllllz 1 7 Sheets-Sheet 4 INVENTOR Samuel Mrbelly.

BY a M H15 ATTORNEY Sept. 8,

s. MlSKE LLY AUTOMATIC CROSSING GATE Filed March 10, 1939 7 Sheets-Sheet5 WM n W .m M

ws S Q mi P 1942- s. MISKELLY 2,295,419

AUTOMATIC CROSSING GATE Filed March 10, 1939 '7 Sheets-Sheet 6 m I 124]0 111 I INVENTOR Samuel 1 151 50149.

Pi- 1942- s. MISKELLY 2,295,419

AUTOMATIC CROSSING GATE Filed March 10, 1939 7 Sheets-Sheet 7 l i i 120%9 '5 am i f I V 7 I B0 129 134 w u 115a I| 125 I 122 62) m b -1 120 O122 f 11a INVENTOR Samuel M'f'belly.

15 ATTORNEY Patented Sept. 8, 1942 UNITED STATES PATENT OFFICE AUTOMATICCROSSING GATE.

Application March 10,

4 Claims.

My invention relates to automatic crossing gates, that is, to gatesadapted to be located adjacent the intersections of highways andrailways for preventing users of the highway from crossing the railwaywhen a train is approaching the intersection.

More particularly, my present invention relates to operating. mechanismsfor gates of the type described, and one object of my invention is topro vide an improved operating mechanism which can be readily mounted onthe same pole which is used to support other conventional warningdevices.

Another object of my invention is to provide a gate operating mechanismwhich is readily adaptable to either the right-hand or lefthand side ofthe highway, and which can be used for operating single or doublebearing gate arms.

A further object of my invention is to provide a mechanism in which themovement of the roadway arm to its lowered or traffic obstructingposition is effected by gravity, and its movement to its raised orproceed position is effected by means of aneleotric motor through afriction clutch and suitable reduction gearing, the arm being held inits proceed or clear position by maintaining electrical energy on a holdclear magnet.

A further object of my invention is to provide a mechanism of the typedescribed which is so arranged that the raised or clear position of thesidewalk arm can be adjusted between limits varying betweenapproximately 72 and 90 from its lowered or traffic obstructingposition.

A further object of my invention is to provide a mechanism which can beequipped when desired with a shaft for operating a sidewalk arm.

A. further object of my invention is to provide a mechanism having alarge number of circuit controlling contacts which can be adjusted toopen or close at any desired point in the travel of the gate arm toenable the contacts to be readily used for controlling the mechanismitself, as well as other warning devices which may be provided.

A further object of my invention is to provide a mechanism which willoperate efiiciently, is rugged in construction, and can be manufacturedat a minimum cost.

Other objects and characteristic features of my invention will becomeapparent as the description proceeds.

I shall describe one form of crossing gate embodying my invention, andshall then point out the novel features thereof in claims.

In the accompanying drawings, Fig. 1 is a front elevational view of acrossing gate embodying my 1939, Serial No. 261,103

invention mounted in the intended manner on a pole or mast together withother customary warning devices, the mechanism being arranged on thesidewalk side of the pole and the main or highway arm I being of thedouble bearing type. Fig. 2 is a left-hand side view of the gatemechanism and associated warning devices shown in Fig. 1. Fig. 3 is anenlarged elevational view of the gate operating mechanism shown in Figs.1 and 2 with the cover removed to better illustrate the construction ofthe various operating parts. Figs. 4, 5 and 6 are sectional views takenon the lines IVIV, V-V and VIVI, respectively, of Fig. 3. Fig. '7 is anenlarged front view of' the hold clear magnet and associated partsforming part of the mechanism shown in Figs. 3 to 6, inclusive. Fig. 8is a right-hand end view of the parts shown in Fig. '7. Fig. 9 is a topview of the lock arm and hold clear magnet assembly forming part of thegate operating mechanism. Figs. wand 11 are vertical sectional views ofthe ratchet wheel assembly R shown in Fig. '7 taken at right angles toeach other. Fig. 12 is an enlarged cross sectional view of the frictionclutch assembly C. Fig. 13 is a back view of the clamping block l3'forming part of the means for securing the mechanism to its supportingpole or mast. Fig. 14 is a diagrammatic View showing one circuitarrangement for controlling the gate operating mechanism.

Similar reference characters refer to similar parts in each of theseveral views.

Referring first to Figs. 1 and 2, a crossing gate embodying my inventionis here shown as comprising the usual roadway and sidewalk arms I and 2operated by a mechanism 3 secured to the lower end of a pole or mast 4.The pole 4 may be located at either side of the highway, as will appearmore fully hereinafter, and in addition to serving as a support for thegate may also be Used as a support for other customary warning devices,here shown as comprising a pair of crossed arms 5 bearing thedesignation railroad crossing, a sign 6 which indicates the number oftracks at the crossing, two pairs of flashing light signals 1, one pairof which faces the crossing and the other pair of which faces away fromthe crossing, and another sign 8 containing the warning stop on redsignal. The various warning devices may be fastened to the pole in anydesired manner, but the fastening means employed should be soconstructed that adequate clearance will be provided between the warningdevices and both gate arms in all positions of the gate arms.

Referring now to Figs. 3, 4, and 6, the mechanism 3 comprises a suitablehousing III, which is closed at its forward end by a removable cover I Ithrough which convenient access to the interior of the housing forinspection or repair of the mechanism may be had. The housing In issecured to the pole 4 by means of two vertically spaced pole clampsdisposed adjacent the top and bottom respectively of the housing, and inorder to facilitate fastening the housing to the pole, the rear wall ofthe housing is formed with a rounded centrally disposed verticallyextending recess l2. Each pole clamp includes a clamping block l3 and apair of bolts l4 disposed on opposite sides of the pole, and to enablethe housing to be readily clamped to any pole falling within the rangeof diameters commonly encountered in practice, the heads of the boltsare disposed in T-shaped transversely extending laterally aligned slotsl5 formed in the rear wall of the housing, and the shanks of the boltsextend through transversely extending laterally aligned slots l6provided in the clamping block l3. (See Figs. 5, 6 and 13.) Furthermore,the clamping block is provided with projections I! (see Fig. 13) whichextend partway into the slots l6 and embrace the bolts in a manner toproperly space them for each diameter of pipe within the range ofadjustment provided for.

The housing is further formed with a wire inlet l8 which is so arrangedthat adapters to suit either flexible conduit, parkway cable, or otherwiring arrangements can be bolted on as required, and with another wireinlet 23 to enable wires to be brought into the housing directly fromthe pole 4. The wire inlet is threaded to receive a pipe nipple 2|, andwhen this inlet is not needed the nipple can be removed and the inletclosed by a sheet metal plate.

The cover ll is made up of a sheet metal portion lla riveted to a castiron rim l lb. The rim ll b is provided with slotted hinge lugs llcwhich hook over a U-bolt 22. Hinge straps lld bolted to the rim llb holdthe cover in position on the U-bolt, but can be readily removed in caseit becomes necessary or desirable to completely remove the cover fromthe housing. A groove He is formed in the rim llb for the reception ofpacking ll 1 which, when the cover is closed, engages against theforward edge of the housing to seal it against the entry of dirt andmoisture, and the nuts 23 on the U-bolt 22 are provided with sufficientadjustment toenable the proper degree of tension on the packing to beobtained.

The cover is fastened in place at the top by a latch assembly (see Fig.5) made up of a handle 24 secured to the outer end of a shaft 25, theinner end of which carries a latch cam 26. The latch cam 26 cooperateswith a depending lug 21 formed on the top wall of the housing Ill. Theshaft is journalled adjacent its outer end in a bushing l lg provided inthe sheet metal portion I la of the cover, and at its inner end in adepending lug I lit formed on the rim llb. The shaft 25 is rotatable bymeans of the handle 24 between a latching position in which the latchcam hooks behind the lu 2'1 and an unlatching position in which itclears the lug 21, and formed in the lower end of the handle is an eye24a which, when the shaft 25 occupies its latching position, engages anapertured lug 28 provided on the cover. It will be obvious that bypassing a padlock through the eye 24a and the lug 28, the cover may belocked against removal by anyone except authorized persons. The latchcam is secured in place on the inner end of the shaft 25 by means of anut 29 in such manner that it can be adjusted to different longitudinalpositions on the shaft to enable the compression of the packing ll 1 tobe adjusted to the desired value.

Mounted in ball bearings 30 (see Fig. 6) disposed in bearing recesses 3|provided in the opposite side walls of the housing l0 is a horizontalshaft 32. The opposite ends of this shaft project outside of thehousing, and are provided with squared portions 33 which receive thehubs of the inain roadway arm, and with screw threaded portions whichreceive nuts 34 (Fig. 2) for securing the hubs in place on the squaredportions. Two sleeves 35 and 35 having a ring 31 of packing disposedbetween them at their outer edges are interposed between each hub andthe associated bearing, and act when the associated nut 34 is tightenedto compress the packing 31 to seal the bearing opening, and also to holdthe bearing in the position on the shaft in which the inner edge of theinner race engages a shoulder 32a formed on the shaft. The outer race ofeach bearing cooperates at its inner edge with a snap ring 38 whichpermits suitable end play. The ball bearings are provided with feltseals on the inside, and provision is made for greasing the bearingswith pressure lubrication.

The mechanism also includes a square shaft 43, one end of which isadapted to receive the hub of the sidewalk arm 2. This shaft extendsparallel to the shaft 32 in vertical alignment therewith, and hassecured thereto at the side walk arm end a journal 4l (see Fig. 3) whichrotates in a bearing 42 machined in the sidewall of the housing ID. Theopposite end of the shaft 40 is machined round, and is journaled in abushing 43 bolted to the sidewall of the housing l0. An end plate 44provided with an opening having an inside diameter which is smaller thanthe outside diameter of the journal 4| is secured to the housing ID atthe outer end of the journal M, and serves with the bushing 43 toposition the shaft 40 lengthwise in the housing.

The shaft 40 as shown in Fig. 3 is arranged with the end which carriesthe sidewalk arm projecting from the left-hand side of the housing. Theparts are so constructed that this end can be made to project from theother side of the housing by interchanging bushing 43 and end plate 44and turning the shaft end for end.

In some installations the shaft 40 may not be required, and when this isthe case, this shaft can be removed and the bushing 43 and end plate 44can be replaced by blank plates to close the openings in the housing.

Secured by means of a set screw 45 to the square portion of the shaft 40is a gear segment 46 (see Figs. 3 and 4) which meshes with a similargear segment 41 secured to the shaft 32. It will be apparent, therefore,that any rotation of the shaft 32 will not only raise or lower theroadway arm, depending upon the direction of such rotation, but willalso similarly raise or lower the sidewalk arm.

The two arms I and 2 are biased by gravity to horizontal positions whichI shall term for convenience stop positions, and are arranged to bemoved to upper or proceed positions by a motor M which is connected withthe shaft 32 through the medium of a friction clutch C and a train ofgears.

The motor M is secured by means of two studs 50 to a partition wall 5|which divides the housing l into two compartments. The studs passthrough clearance holes formed in projecting lugs 52 provided onthe topand bottom respectively of the motor case, and are screwed into tappedholes provided in the partition wall The motor may be of any suitabletype, but as here shown it is a four pole D. C. low voltage series motorwith field, armature, brushes and bearings completely enclosed. Themotor shaft 53 is of special heat treatedspring steel, and extendsbeyond the motor housing at both ends for a purpose which will be madeclear presently.

The friction clutch C is provided to prevent the motor from becomingoverloaded, and also to protect the gear train and shafts from excessivestrains such asmight occur in the, event that the roadway arm I becomesbroken off and the mechanism comes to a sudden stop after moving rapidlyto the clear position. It is mounted on the right-hand end of the motorshaft 53 as viewed in Fig. 3, and in the form here shown comprises afriction disc 54 (see Fig. 12) disposed between a driving flange 55 anda drivenflange 56. The driven flange 56 is formed integrally with apinion 51 comprising part of.

the previously referred to gear train, and the hubs of these two partsare provided with self lubricating bushings 58 which rotatably receivethe motor shaft. The driving flange 55 is splined on shaft 53, and isbiased to the longitudinal position in which the two flanges and thefriction disc are frictionally held together by means of a coil spring59 which surrounds the motor shaft between the driving flange and awasher 60. The washer 60 is also splined on the shaft 53, and isprovided on its outer face with rounded diametrically oppositeprojections 6! which cooperate with rounded diametrically oppositerecesses 62 formed on the inner face of a nut 63 screwed onto the outerend of the motor shaft. It will be apparent that the force required toslip the clutch will depend upon the amount of compression of the spring59, and that the compression of this spring can be readily varied byadjusting nut 53. It will also be apparent that the cooperation betweenthe recesses 62 in the nut 63 and the projections 6| on the springwasher 60 makes the nut self looking in positions a half turn apart,thereby enabling the desired adjustment to be readily obtained.

The previously referred to gear train comprises, in addition to thepinion 51', a first intermediate gear assembly comprising a firstintermediate gear 66 secured to one end of a first intermediate pinion61 and meshing with the pinion 5'5, a second intermediate gear assemblycomprising a second intermediate gear 68' secured to a secondintermediate pinion (59v and meshing with the first intermediate pinion61, and a segmental gear 'Ifl splined to the shaft 32. The firstintermediate gear 66 and pinion 61 are mounted on a shaft H which isjournalled at its ends in roller bearings 12 provided in the housingIll, and the second intermediate gear 68 and pinion 60 are similarlymounted on a shaft 13 which is journalled at its ends in roller bearings14 provided in the housing In. The roller bearings are arranged for oillubrication, and:

are held in place by end plates I5.

The segmental gear it i normally retained in the proper longitudinalposition on the shaft 32 by the previously described gear segment 41(see Fig, 6) which cooperates with the gear segment to drive the shaft40 and by a spacing sleeve 16 pinned to the shaft, and when the sidewalkarm is not required the gear segment 41 is replaced by a suitable sleeve(not shown) which serves to retain the segmental gear 10 in its properlongitudinal position on the shaft 32 under these latter conditions.

The segmental gear 15, in addition to serving as a part of the geartrain for driving the shaft 32, cooperates with two adjustable stopassemblies Si and S2 which are provided to position the gate arms inboth their stop and clear positions. These stop assemblies also providemeans for absorbing shock at the end of the travel of the gate arms innormal operation, when the gate arms are being whipped by high winds,and also when the mechanism is suddenly stopped while moving at highspeed as might happen if the roadway arm I became broken off, and theoperating mechanism subsequently moved at high speed to its clearposition due to the absence of the load normally provided by the roadwayarm.

The stop assemblies S! and S2 are similar and a description of one willtherefore suffice for both. Referring particularly to the stop assemblySI, this assembly is mounted in a cylindrical projection 85 castintegrally with the back wall of the housing is, and comprises a bolt 83which is adjustably screwed into a sleeve 8!, one end of which isprovided with a flange 82. The sleeve 8! is siidably mounted at the endopposite to the flange in an axial hole 33 provided in the outer endwall 8-4 of the projection 85, and is surrounded intermediate its endsby a coil spring 86, one end of which abuts against 131% end wall 84,and the other end of which abuts against the flange 82. The bolt is alsoprovided with a washer 87 which engages the outer end of the sleeve 8|,and with a lock nut 83 which is screwed onto the bolt adjacent the outerside of the washer. A frusto-conical cover 89 is secured to the outerside of the end wall 8 4 and serves to protect the exposed end of thebolt 80.

The stop assembly S2 is mounted in a cylindrical projection 93 which isalso cast integrally with the housing if and the two stop assemblies SIand S?! are so disposed that when the gate arms occupy their stoppositions the edge 9! of the segmental gear "it will engage the head ofthe bolt 85 of the assembly Si, whereas when the gate arms occupy theirclear positions in which they are shown in the drawings, the edge 92 ofthe segmental gear 13 will engage the head of the bolt of the assemblyS2.

Adjustment for positioning the gate arms in either the stop or clearposition is made by loosening lock nut 83 on the bolt 89 of the properstop assembly, and thee turning the bolt by means of the square sectionprovided on its outer end. Sufficient adjustment is provided to takecare of normal manufacturing variations, and also so that the two armsmay be stopped in clear positions varying between the vertical positionsshown in full lines in Fig. 1 and the inclined positions shown in dottedlines, the inclined positions being spaced approximately 12 from thevertical.

It will be apparent that when the segmental gear M moves into engagementwith the bolt 80 of either stop assembly, the bolt will move in thedirection to compress the associated spring 86, whereby the spring willabsorb the shock. The amount the spring 88 can become compressed islimited by means of a stop shoulder a formed at the inner end of thecylindrical projection 85 in a position to be engaged by the flange 82on the associated sleeve.

The mechanism further comprises a hold clear magnet E (see Figs. '7, 8and 9) and holding mechanism controlled thereby for retaining the gatearms in their proceed positions against the action of gravity after theyare moved to these positions by the motor M. These parts are allenclosed within an auxiliary casing 96 which is secured to the left-handend of the motor M, as viewed in Fig. 3, by means of two filister handscrews 9'! (Fig. 7), and it will be seen, therefore, that by removingthe screws 91, the entire casing with the various parts mounted thereincan be removed as a unit from the mechanism 3. The casing is closed byan aluminum cover I98 which is held in place by a snap spring 99 and aleaf spring i To remove the cover, the snap spring 99 is first released,and the cover is then pulled toward the right, as viewed in Fig. 7.

The hold clear magnet E comprises two parallel magnetizable cores 38secured together at one end by means of magnetizable bar IE5, andprovided at the other end with enlarged pole pieces I35. The cores 98 arpressed at the ends which are provided with the pole pieces into holesin a non-magnetizable bracket I01, and are riveted to the bracket bymeans of suitable rivets (not shown) which pas through aligned holesformed in the bracket and in the pole pieces. Mounted on the cores aremagnet coils I09 which, as will appear hereinafter, include a pick-upwinding and a holding winding.

The bracket It! is secured to the casing 95 by means of three screwsIHJ, III and H2. The cores 98 and coils I99 are disposed horizontally toconserve space, and the coil are located outside of the casing 96 tofacilitate assembly and maintenance. The cores at the ends which areconnected by the bars I35 are anchored securely to the casing 35 toprevent any vibration or other movement from affecting the relationbetween the magnet assembly and the casing.

The pole pieces I35 of the electromagnet cooperate with an armature H5.Thi armature is yieldably attached to an armature support H6 ofnon-magnetizable material, such as cast aluminum, by means of spacedstuds III! which are secured to the armature and which extend throughclearance holes I19 in the support, and compressed coil springs IIBawhich surround the studs between the support and castellated nuts I20screwed onto the outer ends of the studs. The nuts I20 are locked inadjusted positions on the studs by cotter keys I2I.

The armature support I I 6 is provided at its upper end with a pair ofspaced lugs I22, and with a curved arm I23, and is pivotally attached bymeans of a pin I to a bracket I24, bolted to the upper side of thebracket I 31. The pin I25 passes through clearance holes in the lug I22and in spaced lugs I25 formed on the bracket I24 and disposed onopposite sides of the lugs I22. The arm 23 carries a pin I2'I the endsof which extend into elongated slots I28 formed in spaced plates 29comprising part of a lock arm assembly.

This lock arm assembly is pivoted at the end opposite to the arm :23 ona pin I36 mounted in a block I3l secured to the casing 55, and isprovided intermediate its ends with a pivoted looking pawl I32 whichcooperates with a ratchet wheel assembly R. mounted on the motor shaft53. The pawl I32 is biased by means of a spring I34 in a clockwisedirection, as viewed in Fig. '7, to a position in which it engages astop pin I35 mounted in the spaced plates I29. The spring I34 is securedat one end to the pawl and at the other end to a tie bar I36 riveted tothe plates. The parts are so proportioned that when the electromagnet Ebecomes energized and attracts the armature IE5, the armature will actthrough the armature support H6 and pin I21 to move the lock armassembly to an upper position in which the teeth provided on the pawl I32 mesh with teeth provided on the ratchet wheel of the ratchet wheelassembly a shown in Fig. 7, but that, when the electromagnet isdeenergized, the lock arm assembly will drop by gravity to a position inwhich the teeth on the pawl I32 are out of engagement with the teeth onthe ratchet wheel of the ratchet wheel assembly and will act through thepin I21, and armature support to rotate the armature .I I5 away from theelectromagnet to a released position. To insure that the force ofgravity will exert sufficient torque on the assembly to cause it to dropto the desired position the arm may be Weighted by any suit able means,such for example, as a metal block (not shown) riveted between th plateadjacent the end which is pivotally connected to the armature support.

The ratchet wheel assembly R (see Figs. 10 and 11) comprises two arcuatesegments I40 and I 4I clamped in diametrically opposite positionsbetween a ratchet wheel M2 and a circular plate I43 by means of screwsI44. The ratchet wheel and plate are loosely journalled on the motorshaft 53 on opposite sides of a driving piece I 45 which is keyed to theshaft and the whole assembly is positioned lengthwise on the shaft bymeans of the ratchet wheel I42 which is disposed between a shoulder formd on the shaft and a washer I45 held in place by a castellated nut I41provided with a cotter key I4Ia. Sufficient clearance is providedbetween the washer and the ratchet wheel to permit the ratchet wheel andplate I43 to rotate freely on the motor shaft. The driving piece I45 isformed with fan shaped ends, and disposed between two of the radiallyextending sides of these ends and the adjacent radially extending sidesof the segments I41) and MI are recoil springs hi8 (see Fig. 19) whichnormally maintain the ratchet wheel I42 and plate I43 in a predeterminedangular position relative to the driving piece, but which permit alimited amount of angular movement between the ratchet wheel and plateand the motor shaft in one direction if sufficient force is exerted tocompress these springs. The assembly is closed at its outer edge by aring I49 which is pressed onto the plate I43 and the one side of whichabut against the inner side of the ratchet wheel. The previouslyreferred to teeth which cooperate with the teeth on the pawl I32 areformed on the outer edge of the ratchet wheel.

When the motor M is rotating in the direction to raise the gate arm, theratchet wheel assembly will be rotated in a clockwise direction, asviewed in Fig. 7, and it will be apparent that with the ratchet wheeland latch arm assemblies constructed in the manner just described, ifthe magnet E is then energized, so that the latch arm assembly is heldin its upper position, the teeth on the ratchet wheel assembly willcooperate with the teeth on the pawl I32 to rotate the pawl inopposition to the bias of the spring I 34 to a position in which theteeth slip past each other. As soon, however, as the motor stopsrotating, the

pawl will immediately move to the position in which it engages the stoppin I35 and will thus prevent the motor shaft from rotating in thedirection to permit the gate arms'to move to their stop positions aslong as the magnet E remains energized. The function of the springs I48is to cushion the parts against shock when the gate arms first becomelatched in their clear positions, or sway in the wind after becominglatched in their clear positions.

It should be pointed out that the springs IIBa which comprise part ofthe means for securing the armature II to the armature support H6 givespecial assurance against the holding device becoming improperlyreleased under adverse conditions.

It should also be pointed out that the parts of the lock arm assemblyand ratchet wheel assembly are so arranged that they can be assembledfor either right-hand or left-hand operation. As shown in the drawingsthey are assembled for left-hand operation, and when it is desired toassemble them for right-hand operation all that needs to be done is tomove the stop pin I35 from the position shown to the holes I5I in theplates I29, remove spring I34 from the lower hole in the pawl I32 andplace it in the upper hole, and remove the recoil springs I48 and placethem on the opposite sides of the driving piece I45.

The armature support H6, in addition to being operatively connected withthe lock arm assembly, operates contact mechanism the function of whichwill be made clear presently. As here shown, this contact mechanismcomprises two movable contact fingers I55 and I56 mounted at one end onan insulating block I51 secured to the support H6, and provided at theiropposite ends with low resistance contact members which engagecooperating low resistance contact members formed on fixed contactfingers I58 and I59 or I60 and I6I to close front contacts I55- I58 andI56-I59 or back contacts I55-I60 and I56I6I according as the armatureII5 occupies its attracted or its'released position. The fixed contactfingers I58 and I59 are secured by means of an insulating block I62 tothe support I24, and are both electrically connected by means ofsuitable wires with a terminal post I63 mounted in an insulatingterminal block I65 provided on the top of the casing 96. The fixedcontact fingers I60 and I6I are similarly secured by means of aninsulating block I66 to the support I24 and are both electricallyconnected by means of suitable wires with a terminal post I61 mounted inthe insulating terminal block I65. The movable fingers I55 and I56 areconnected by means of suitable wires to the lower end of a terminalstrip I68 mounted on block I66, and the strip I68, in turn, is connectedat its upper end by a suitable wire with a terminal post I69 mounted inan insulating terminal block I provided on the top of casing 96. The twoterminal blocks I65 and I10 are provided with other terminal posts forthe reception of the leads for the two windings of electromagnet E.

A terminal block I1I is secured to the outer side of the casing 96adjacent its lower righthand corner, as viewed in Fig. 3, and hasmounted thereon an adjustable resistor I12 for a purpose which will bemade clear presently.

The mechanism also comprises a suitable circuit controller CC which isprovided for'governing the various circuitswhich control the mechanism,as well as certain ones of the other warning devices. This circuitcontroller in the form here shown comprises a plurality offlexiblecontact fingers I15, I16, I11, I18, I19, I80, I8I, I82, I83 andI84 which cooperate respectively with fixed front contact fingers I15a,I16a, I11a, I10a, I19a, Ia, I8Ia, I82a, I83a and I64a to form frontcontacts I15--I15a, I15-416a, I11-I11a, I18-I18a, I19-l19a, ISO-30a,I8II8Ia, I82--I82a, I83-I83a and I84-I94a. The flexible contact fingersare secured by means of terminal posts I85 within slots I66 formed in aninsulating terminal board I81, and the fixed contact fingers aresimilarly secured by means of terminal posts I88 within slots I89 formedin an insulating terminal board I90. The flexible contact fingers mayalso be made to cooperate with fixed back contact fingers, only two ofwhich I831) and I841) are shown in the drawings. These latter fingersare secured to the terminal board I90 in a manner similar to the otherfingers but when both fixed front and back contact fingers are provided,the two sets of fixed fingers will be offset from each other in themanner shown.

The two terminal boards I81 and I90, in turn, are secured at theiropposite ends to two connecting bars I9I by means of bolts I92, and thecontact assembly thus formed is secured as a unit by means of stud boltsI93 to lugs provided on the housing I0.

The flexible contact fingers are all biased by their own resiliency topositions in which the front contacts formed thereby are closed, and arearranged to be moved to their open positions in which the back contactsbecome closed by means of cams I94 which are secured to the shaft 32,and which cooperate with insulating cam followers'l95 secured to thefingers. Each cam comprises an operating portion I94a. and a clampportion I941) secured together by means of an adjusting screw I940 and aclamping bolt I94d. Each adjusting screw I94c cooperates intermediateits ends with an annular threaded groove I96 formed in the shaft 32 insuch manner that by first backing off the nut on the clamping bolt I94dand then rotating the adjusting screw I94c the cam can be readily movedto any desired angular position relative to the shaft. After the desiredadjustment has been made, the clamping bolt is again tightened and thecam will then be securely held in its adjusted position.

The face of each cam is made relatively wide and the cams are soconstructed that they can be assembled on the shaft in either of twopositions in one of which the cam face will be directly opposite anassociated one of the movable contact fingers, and in the other of whichthe face of the cam will be midway between two fingers. With thisarrangement, each cam can be made to operate 1, 2 or 3 contacts toprovide any desired contact combinations by assembling the cam on theshaft in the proper position, and by the proper choice of cam followers.For example, if it is desired to operate only one contact from a cam,the flexible finger of this contact will be provided with a cam followerwhich is only slightly wider than the finger, as shown in connectionwith the finger I15, and the associated cam will be assembled on theshaft in the position in which its cam face is directly opposite thefollower. If, however, it is desired to operate tWo contactssimultaneously by means of the same cam, a follower which isapproximately twice as long as the follower secured to the finger I15will be secured to both fingers,

as shown in connection with the fingers I16 and I17, and the associatedcam will be assembled with its cam face midway between the fingers. Whenit is desired to operate three contacts simultaneously a follower whichis long enough to bridge all three of the flexible fingers will besecured to the flexible fingers, as shown in connection with the fingersI78, H9 and I89, and the associated cam will be assembled on the shaftin the position in which its cam face is directly opposite the middlefinger. It will be apparent from an inspection of the drawings that theshaft 32 is provided with as many grooves I95 as there are contacts, andthat one of these grooves is located opposite each contact. The partsare so proportioned that when any cam follower is engaged by the face ofthe associated cam, the finger or fingers to which it is attached willbe moved to such position or positions that the back contact or contactscontrolled thereby will then be closed and the front contacts will beopen.

Referrin now to the wiring diagram for the gate shown in Fig. 14, ashere illustrated motor M is provided with an energizing circuit whichpasses from a suitable source of current here shown as a battery Dthrough contact I'.SI?6a of circuit controller CC, contact I 55-453controlled by electromagnet E connected in multiple with contact I56I59controlled by electromagnet E, the armature 233 of motor M, and seriesfield winding 295 of motor M back to battery D. This circuit is closedwhen and only when electromagnet E is energized and contact ITS-416a isclosed, and the parts are so arranged that when this circuit is closedthe motor will operate in a direction to move the gate arms toward theirclear positions. The contact I'I5-I'-'6a is so adjusted that it will beclosed at all times except when the gate arms occupy their upper orclear positions, which will usually be somewhere between 72 and 90degrees from their stop positions, and it will be apparent, therefore,that when the energizing circuit for motor M becomes closed the motorwill move the gate arms to their clear positions, whereupon contactII6-I7Ea will open and will deenergize the motor.

Motor M is also provided with a snubbing circuit which may be tracedfrom the upper terminal of armature 293 through contacts I55-I5IJ and I555-461 of electromagnet E connected in multiple, adjustable resistorI72, and field winding 234 back to the other terminal of armature 253.This circuit is closed whenever electromagnet E is deenergized, which aswill appear presently, is the case when the gate arms are descending,and its purpose is to cause the motor to function as a generator duringthe descent of the gate arms and thus act as a brake to retard thedescent of the arms. As will be readily understood, the braking effortexerted by the motor when this circuit is closed depends upon theresistance of this circuit, and it will be seen, therefore, that byadjusting the resistor I'l'2 to different values this braking effort canbe readily varied within certain limits.

The pick-up winding of electromagnet E is designated by the referencecharacter 20B, and is provided with a circuit which passes from batteryD through front contact 208 of a relay TR, contact I'll-Illa of circuitcontroller CC, winding 205 of electromagnet E, front contact 2II ofrelay TR, and wire 2I2 back to battery D.

Relay TR will usually be controlled by a track circuit not shown, andwill be energized at all times except when a train is approaching thecrossing adjacent which the crossing gate is located.

The contact II7-I'I'Ia of circuit controller CC is adjusted to open atthe same point in the stroke of the gate arms as contact I'I6-I'I6a, andit will be seen. therefore, that whenever track relay TR becomesenergized winding 206 will become energized provided the gate arms thenoccupy any positions but their upper or clear positions. The parts areso proportioned that when winding 265 is energized, armature II 5 willmove to its attracted position in which the pawl I32 engages ratchetwheel I42, and in which contacts I55-i53 and ISIS-I59 are closed, andcontacts I55-I50 and I55-I6I are open.

The holding winding of electromagnet E is designated by the referencecharacter 201, and is provided with a circuit which passes from batteryD through front contact 208 of relay TR, winding 29? of electromagnet E,front contact 2II of track relay TR, and wire 2 I2 back to battery D.This circuit is closed whenever relay TR. is energized, and the partsare so proportioned that the winding 20'! will require less energizingcurrent than winding 206, but when energized will cause sufiicient forceto be exerted on armature II5 to hold it in its attracted position onceit has been moved to this position.

As shown in the drawings, all parts occupy the positions which theynormally occupy when no train is approaching the crossing. That is tosay, relay TR is energized, the holding winding 20! of electromagnet Eis energized and the pick-up winding 206 is deenergized, motor M isdeenergized, and the gate arms are held in their upper or clearpositions by engagement of the pawl I32 with the ratchet wheel I42 ofthe ratchet wheel assembly R.

In explaining the operation of the crossing gate as a whole, I shallassume that relay TR becomes deenergized due to a train approaching thecrossing. The deenergization of relay TR will interrupt, at its frontcontacts 208 and 2H, the circuit which was previously closed for theholding winding 29! of electromagnet E, and since both the pick-up andholding windings are then deenergized, electromagnet E will becomedeenergized. When electromagnet E becomes deenergized, the force exertedby armature I I5 on the lock arm assembly will be removed, and the lockarm assembly will therefore move, due to its gravity bias, to itslowermost position, thereby moving pawl I32 out of engagement withratchet wheel M2, and armature H5 to its released position in whichcontacts I55-I58 and ISIS-I59 become opened and contacts I55-I60 andI56-I6I become closed. The movement of pawl I32 to its released positionwill remove the force which previously prevented armature 203 of motor Mfrom rotating, and the gate arms will therefore start to descend byvirtue of their gravity bias, and will act, through the previouslydescribed gear train and friction clutch C, to rotate the motor in theopposite direction to that in which it rotates by virtue of itsenergizing circuit. The closing of contacts I55-I60 and ISE-IBIcompletes the snubbing circuit for motor M, and since the motor is nowrotating in the opposite direction from that which it rotates when it isenergized by its energizing circuit, the motor will function as agenerator, and will thus exert a braking force on the gate arms. As waspreviously pointed out, this braking force depends upon the adjustmentof the resistor I12, and this resistor will be so adjusted that it Willcause the gate arms to descend at the desired slow rate. When the gatearms reach their'horizontal or stop positions, the segmental gear 19will move into engagement with the head of bolt 80 of the stop assemblySI, which will cause the spring 86 of this stop assembly to becomecompressed and thereby stop the further descent of the gate arms withoutshock. The rotation of the shaft 32 which takes place during the descentof the gate arms will of course operate the contacts of the circuitcontroller CC in accordance with the settings of the various cams, itbeing remembered that the two contacts lit-[16a and ilk-Illa. areadjusted to become closed as soon as the gate arms move away from theirfull clear positions.

I shall now assume that with the gate arms in their lowermost or stoppositions relay TR becomes energized. Under these conditions, theresultant closing of contacts 268 and 2 ll of relay TR will complete thepreviously described circuits for both the pick-up winding 206 andholding winding 29'! of electromagnet E, and these windings will causearmature H5 to move to its attracted position. The movement of armatureH5 to its attracted position will open contacts i55'5il and l56-l6l andwill close contact l55--l58 and contact l$fi-l59, thereby interruptingthe snub-hing circuit for motor M and completing its energizing circuit.Motor M will therefore become energized, and will act through thefriction clutch C and the previously described gear train to move thegate arms toward their upper or clear positions. The movement of thearmature M5 to its attracted position will also move the lock armassembly to its upper position in which the pawl E32 engages the ratchetwheel I42, but since the motor is now rotating in the direction to raisethe arms, the ratchet wheel teeth will merely rotate the pawl I32 awayfrom stop pin i355 in opposition to the bias of the spring I34 to theposition in which the teeth on the ratchet wheel slip past the teeth onthe pawl. When the gate arms reach their upper or clear positionscontact l'lE-ll'fia of circuit controller CC will open and willdeenergize motor M, and contact I'll-417a of circuit controller CC willalso open, and will deenergize the pick-up winding 266 of electromagnetE. Winding Zill of electromagnet E will remain energized, however, andpawl I32 will therefore now cooperate with the ratchet wheel M2 to holdthe gate arms in their upper or clear positions. The stop assembly S2 isso adjusted that the segmental gear will move into engagement with thebolt 80 of this assembly substantially simultaneously with the openingof the contacts FIB-416a and I'll-411a, and it will be seen thereforethat this stop assembly will act to bring the gate arms to rest in theirupper or clear positions without shock. The friction clutch C willpreferably be so adjusted that as the gate arms come to rest the clutchwill slip sufficiently to prevent shock to the gearing due to theinertia of the motor armature. When the gate arms finally come to restall parts will then be restored to the positions in which they are shownin the drawings.

It should be pointed out that in actual practice, the gate arm I willusually be provided with a suitable counterweight which will be soarranged and so proportioned that as this gate arm descends the momentof the counterweight will increase faster than that of the arm, so thatthe resultant moment will become less and less until the arm reaches thehorizontal or stop position, at which time the turning moment of the armper se and that of the counterweight will be practically equal. Thisfeature insures rela tively quick starting of the arms downwardly whenthe electromagnet E becomes deenergized, and also insures the lowesttorque when starting the arm upwardly on application of current to themotor to restore the arm to its clear position. Furthermore, the highturning torque at the start of the arm from the clear position rapidlyturns the motor in reverse direction, and generates a counter E. M. F.which quickl produces a snubbing action at the start. Stated in anotherway, the counterweight is so positioned and of such size that the gatearm will fall rapidly for the first five degrees or so, and will thencontinue to descend at practically constant speed after the snubbingaction takes efiect due to the motor having picked up speed. Thegearing, of course, will assist in retarding the descent of the gate armby virtue of its inherent friction.

It should also be pointed out that while as shown in Fig. 1, the gatemechanism is located on the sidewalk side of the pole, the mechanism canreadily be turned through an angle of 180 relative to the pole to permitit to be located on the street side of the pole. Furthermore, the gatearm I can be secured to the shaft 32 with the arm at either side of thepole, and this gate arm 'I which is of the double bearing type, that isto say, of the type having a hub secured to each end of the shaft, canbe replaced by a gate arm of the single bearing type, that is to say,one

in which the arm has only one hub which is secured to one end or theother of the shaft 32. When a single bearing type of arm is used, theend of the shaft which does not have the arm attached to it, will beprovided with a sleeve of the same length as the hub of the arm tomaintain the proper bearing seal.

Under some conditions of operation it may be desirable to determine thenumber of times the gate has operated within a given period, and forthis purpose a suitable counter V is provided. This counter is securedto the right-hand bar [9| of the circuit controller CC, as viewed inFig. 3, and is provided with a weighted arm 220 which cooperates with alaterally projecting post 22l secured to the right-hand cam H4 in suchmannor that the counter will be operated once for each operation of thegate arm.

One advantage of a gate mechanism embodying my invention is that it canbe adapted for use under all types of operating conditions, which makesit universal in its applications.

Another advantage of a gate mechanism embodying my invention is that allparts of the mechanism are readily accessible and can be readily removedfrom the mechanism for inspection, adjustment, repair or to adapt themechanism to any special operating requirement.

Another advantage of a gate mechanism embodying my invention is that byadjusting the spring stop assemblies SI and S2, which may be readilydone by merely removing the covers 89, the gate arms can be adjusted tooccupy any clear position falling between approximately 72 and from thelowered or horizontal positions.

Although I have herein shown and described only one form of crossinggate embodying my invention, it is to be understood that various changesand modifications may be made therein within the scope of the appendedclaims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In a highway crossing gate, in combination, a housing provided withtwo cylindrical projections each provided at its outer end with an axialhole, two sleeves one slidably mounted in each of said holes and eachprovided with a screw threaded axial hole and with a flange at one end,two bolts one screwed into the threaded hole in each sleeve and eachprovided at its outer end with a nut, two compressed coil springs onesurrounding each sleeve between the associated flange and the outer endof the associated projection and each biasing the associated sleeve toan inner position which depends upon the adjustment of the associatednut, a rotatable shaft journalled in said housing, means secured to saidshaft and adapted to engage said bolts for limiting the movement of saidshaft between two extreme positions, and a gate arm secured to saidshaft and rotatable therewith.

2. A highway crossing gate comprising a housing adapted to be secured toa signal pole, a main gate arm shaft journalled in said housing, a maingate arm secured to said main gate arm shaft and biased by gravity to astop position, power means in said housing operatively connected withsaid shaft for moving said main gate arm in opposition to its bias to aclear position, a sidewalk arm shaft having secured thereto adjacent oneend a journal which rotates in a bearing machined in the one sidewall ofsaid housing and having the other end journalled in a bushing bolted tothe opposite sidewall of said housing, an end plate surrounding saidsidewalk arm shaft and bolted to said housing adjacent the outer end ofsaid journal and engaging the outer end of said journal to hold saidshaft in place in said housing, said sidewalk arm shaft being of suchlength that the end adjacent said journal projects outside of saidhousing far enough to receive a sidewalk arm and being operativelyconnected with said main gate arm shaft to operate in unison therewith,and the parts being so constructed that the end of said sidewalk armshaft which carries the sidewalk arm can be made to project from theopposite side of said housing by interchanging said bushing and said endplate and turning said shaft end for end.

3. A highway crossing gate comprising a housing adapted to be secured toa signal pole, a main gate arm shaft journalled in said housing andcarrying a main gate arm biased by gravity to a stop position, powermeans in said housing operatively connected with said main gate armshaft for moving said main gate arm in opposition to its bias to a clearposition, a sidewalk arm shaft having a sidewalk arm secured to one endthereof, means for journalling said shaft in said housing in such mannerthat the end carrying the sidewalk arm can be disposed at either side ofthe housing, and means for operatively connecting said two shaftstogether to cause them to operate in unison.

4. In a highway crossing gate, in combination, a housing provided with acylindrical projection having an axial hole at its outer end, a sleeveslidably mounted in said hole and provided with a screw threaded axialhole and with a flange at one end, a bolt screwed into the threaded holein said sleeve and provided at its outer end with a nut, a compressedcoil spring surrounding said sleeve between said flange and the outerend of said projection and biasing said sleeve to an inner positionwhich depends upon the adjustment of said nut, a member mounted torotate within said housing and adapted to engage said bolt for limitingthe movement of said member in one direction, and a gate arm operativelyconnected with said member.

SAMUEL MISKELLY.

